For most of probable electric devices, battery is always a main power. However, due to a limited extent volume of the probable electric devices have, only a confined electrical capacity the battery is stored. Thus, to design a device with low power consumption has been longing for by the related product design engineer. Consequently, nowadays for those advance products, the probable devices having a battery management chip therein to manage battery related parameters such as remaining capacity, working environmental temperature, status of the charging/discharging, accumulation times, EDV 2 (End of discharge voltage) become main stream. A smart battery management chip further comprises the related parameter updating capability.
Generally, a battery management chip comprises microprocessor having a CPU, ROM, RAM and a battery protection integrated circuit. The ROM contains a battery management program of about remaining capacity monitoring and calculation, display, keyboard other than a booting program. The CPU fetches instructions of programs to monitor the remaining capacity of the battery and store the results into the RAM or show on the display. However, some of the battery related parameters based on for calculating the remaining capacity, charging saturation value of the battery are not invariable after using a period of time due to the chemistry decay or aging. And, ROM is incapable to bear burden to record the parameters and/or learning program. The flash memory seems to be a good candidate for data storage over 10 years without any power. Hence, a smart battery management chip internal embedded with a flash memory therein to record the learning program are demanded so as to retain the updating data for next time use.
With the advent of the semiconductor manufacture technology, nowadays, popular processes of device length are about 90 nm or beyond to achieve low operating voltage, low tolerance voltage of flash memory having is inferior to let it concurrent manufactured with other components of the battery management chip. Since the trend is toward more cells in one battery train so as to avoid embarrassed situation of breaking out and really breaking away from AC adapter while user operates the probable device in a predetermined time. As a result, the operation voltages for such configuration of the battery become rather high and so does the battery management chip. Typically, the voltage range is from 7.5V to 40V. Thus, to accommodated most of the clients, a battery management chip should have a working voltage range within 30V to 40V, which are out of range of current flash memory in the market.
As forgoing problems, an object of the present is thus to develop a battery management chip with new configuration to overcome aforementioned problems. The present invention thus disclose a configuration embedded with SRAM and cache SRAM along with a external flash memory module so that it can still retain the most newly parameter obtained from the learning program after the probable device is turned off.